Light emitting diode (LED) driver circuits are often called upon to drive a number of series connected strings of diodes simultaneously. The strings of diodes (or “LED channels”) may be operated in parallel, with a common voltage node supplying all of the strings. A DC-DC converter (e.g., a boost converter, a buck converter and so forth) may be employed by the LED driver circuit to maintain a regulated voltage level on the various LED channels during operation so that all LED channels have adequate operational power. Feedback from the LED channels may be used to control the DC-DC converter. To reduce unnecessary power consumption, it is desirable to keep the regulated voltage level on the voltage node to a minimum or near minimum, while still providing adequate power to all channels. One commonly used technique to adjust the brightness from LED string is to rapidly turn on/off the LED current using a PWM (pulsed width modulation) dimming signal. The average luminous output is thus proportional to the duty cycle of the PWM dimming signal.